A typical RF transmit and receive chain are shown in FIGS. 1a and 1b respectively. The transmit circuitry includes a power amplifier (PA) system. In PA system design, one major design goal is high efficiency, which is especially important for wireless applications. For example, high power is desirable for a base station to increase range, whereas low power is desired in a terminal to reduce power consumption
One way to improve the efficiency performance of a PA system is to add additional PA components in the system, such as by providing a 2-component PA system, as illustrated in FIG. 2.